Portable carbon dioxide fire extinguishers are mainly composed of spray canisters, opening and closing valves, and barrels.
Portable carbon dioxide fire extinguishers are to exhaust the air, so that the fire lost oxygen extinguished, can be used in class B, C and E fire. Because carbon dioxide is a gas that does not remain, it can be used on electric fires to avoid damage to equipment. (Carbon dioxide can be used on Class A fires, but it must be used for a long period of time, and it is unlikely that a portable fire extinguisher will be able to provide a sufficient dosage.) Carbon dioxide extinguishers usually have a cylinder at the top of the nozzle.
Because carbon dioxide is very cold when stored in an extinguisher, care should be taken to avoid contact with it when using it to avoid frostbite. Portable dry powder, water-based (storage pressure) fire extinguishers mainly by the cylinder, head (valve), spray (head) tube, safety pin, extinguishing agent, drive gas (generally nitrogen, with the extinguishing agent together in the extinguisher cylinder, the rated pressure is generally 1.2 ~ 1.5MPa), pressure gauges, and nameplates and other components.
In the standby state, the pressure of the driving gas in the fire extinguisher is displayed through the pressure gauge in order to determine whether the fire extinguisher failure.
Carbon dioxide fire extinguishers when using the precautions
Fire extinguishers as long as the extinguisher will be raised to the fire scene, in the distance from the burning material about 3m to put down the fire extinguisher, pull out the safety pin, one hand to hold the horn cylinder root of the handle, the other hand to hold tightly to start and stop the valve of the pressure handle. For carbon dioxide fire extinguishers without a spray hose, the flapper should be wrenched upward by 70° to 90°. When extinguishing the fire, when the combustible material is burning in the form of a stream, the user will spray the jet of carbon dioxide extinguishing agent toward the flame from near to far.
If the combustible liquid burning in the container, the user should raise the horn, from the container side of the upper part of the burning container spray, but can not make the carbon dioxide jet directly impact on the surface of the combustible liquid, in order to prevent the combustible liquid will be washed out of the container and expand the fire, resulting in extinguishing the fire difficult. The use of carbon dioxide fire extinguishers to fight electrical fires, if the voltage exceeds 600V, should be disconnected first after extinguishing.
It should be noted that the use of carbon dioxide fire extinguishers, outdoor use, should choose to spray in the upwind direction, the use of appropriate gloves, can not directly grasp the outer wall of the horn cylinder or metal connecting tube, in order to prevent the hand from frostbite; in the indoor use of small space, the operator should quickly leave after the fire to prevent asphyxiation.